The Relationship Between The Reproductive Performance Of Hyperprolific Primiparous Sows And The Nutrient Cost Of The Piglet

A one-factor experiment was designed to investigate the relationship between the reproductive performance of hyperprolific primiparous sows and the nutrient cost of the piglet Twenty-one LandranceX Meishan crossbred gilts, which were littermate or semi-Iittermate with similar body weight at similar age, were chosen and kept in the same enviromental conditions (housing, management, feeding) up to approximately 96.70?.01kg, were natrurally inseminated by the same healthy, strong Landrance boar at the age of about 1.5, whose semen quality and insemination rate were high, allotted to 4 treatments (high, NRC, middle and low Plane of nutrition) at random. Each treatment consisted of 6 gilts (high Plane of Nutrition consisted of 3 gilts). The experimental diet was corn and soya bean meal containing 3.2McalDE and 15%CP. During gestation, the sows in each treatment were fed the assigned amount of experimental diet, in early gestation fed the sows 2.0, 1.2, 1.0 and 0.6 fold of energy for mantaince, the feed intake increased 20% in mid-gestation and 50% in late gestation. All sows were allowed ad libitum access to lactational diet during lactation.The results showed:1. During gestation, fed primiparous sows high Plane of Nutrition increased feed cost per piglet; although low Plane of Ntrition decreased the feed cost at birth, could not meet the nutrition need of sows, induced stereotypic behaviour and decreased piglet viability.2. The corelationship between the reproductive performance and the nutrient cost of piglet was significant, the feed cost per piglet barn alive or weaned was adversely related with the litter size born alive or weaned (P<0.05 or P<0.01).3. During gestation, it is proper to feed LandranceX Meishan primiparous sows with NRC Plane of Ntrition. there was a significant (P<0.01 or PO.05) linear decrease in the feed cost per piglet (4.089kg and 4.977kg) as the litter size bom alive* or weaned increased. If put LandranceX Meishan primiparous sows into practice, to get the same number of piglets weaned per year, there would be 1/3 decrease in the number of sows fed thoughout our country.